| The progress of information technology continues to promote the revolutionary upgrading of social productivity and will always be accompanied by the development of human science,technology and civilization.With the integration of traditional silicon-based chips getting closer to the physical limit,researchers urgently hope to replace the traditional electrons with photons as the carrier of information.The optical signal in surface plasmom can break through the diffraction limit,which is expected to achieve this alternative.Two-dimensional(2D)materials have attracted extensive attention since their inception.The addition of 2D semiconductor material black phosphorus(BP)has expanded and improved the research and development of surface plasmon.Anisotropic BP has many characteristics such as direct bandgap,high switching ratio and biocompatibility.The strong localization and dynamic adjustability of the optical conductivity of BP plasmon make it have great potential in the field of micro and nanophotonics.In this dissertation,the coupling mechanism of BP surface plasmon polaritons is deeply studied using the finite difference time domain method,coupled-mode theory and transfer matrix theory,and different micro-nano structures are gradually introduced to analyze its unique optical properties.The phenomenon of strong coupling between excitons and surface plasmons in metals.The research on BP in this dissertation includes the following aspects:1)Considering the poor dynamic tunability of plasmon-induced transparency(PIT)and weak slow light effect of metal waveguide,a periodic structure based on non dispersive dielectric and patterned singlelayer BP nano sheet is designed.The electrical properties of anisotropic BP in plane were studied theoretically from the perspective of conductivity.The optical transmission characteristics of the system are numerically simulated by using the finite difference time domain method,and the coupled mode theoretical model is further established to reveal the mechanism of PIT phenomenon.By changing the carrier concentration of BP,the resonance intensity and resonance frequency of PIT phenomenon can be dynamically adjusted.When studying the slow light effect of the system,a high group index is obtained,which provides a reference for the design of new slow light devices.2)Concerned that the absorption performance of BP is obviously better than the transmission performance,a plasmon-induced absorption(PIA)system based on upper and lower BP nanoribbons and easy to implement is constructed,and a gold mirror is constructed at the bottom of the structure as the substrate to realize the perfect absorption performance.The physical mechanism of the PIA phenomenon is intuitively analyzed by coupling mode theory and electric field distribution diagram.By increasing the spacing between the upper and lower layers of BP nanoribbons and changing the carrier concentration,the influence of the cancellation interference intensity of the two modes on the PIA effect is analyzed.The effects of the polarization angle of the incident light and the gold mirror at the bottom of the structure on the absorption performance of the system are analyzed.The system has excellent absorption performance and dynamic adjustability.It is an ideal platform for realizing optical absorbers and modulators.3)Aiming at the characteristics of in-plane anisotropy of BP,a combined structure of unpatterned monolayer BP sheet and patterned silver nanocycle and a gold mirror at the bottom is proposed.Revealing the general rule for enhanced absorption performance of Fabry-Perot cavities composed of dielectrics and gold mirrors and utilizing surface plasmon resonance between silver nanoribbons or silver nano square and BP nanosheets to achieve efficient light absorb.When the silver in the system is nanoribbons,we change the placement direction of BP.When the silver in the system is a nano square array,we change the polarization angle of the incident light.The influence of structural anisotropy of BP metamaterials on the system is comprehensively studied in these two ways.The proposed anisotropic structure has high optical absorption performance,which provides a basis for constructing plasmon sensors and polarization switches.4)Combining the advantages of BP and graphene,a hybrid structure composed of upper periodic BP nanobelts and lower complete graphene sheets was designed.The theoretical calculation and numerical simulation of the transmission characteristics of the structure are carried out,and the results are consistent.The destructive interference of two excited state modes in the structure leads to an obvious induction window,and two ultra-high performance absorption channels are obtained.By adjusting the carrier concentration of BP and the Fermi level of graphene,the dynamic adjustment function can be realized,and the excellent absorption performance is not affected in the adjustment range.Using the rapid reversal of optical phase at the position of plasmon resonance,a highsensitivity plasmon phase sensor is realized,which provides a potential application reference for plasmon devices based on 2D metamaterials.5)In order to explore the semiconductor properties of BP,a structure composed of BP and gold substrate is constructed,which shows the strong coupling phenomenon of exciton plasmon.Under the excitation of the top prism,excitons are generated in the single-layer BP,and the plasmon remains on the gold surface.The angular resolution of the hybrid system is simulated by using the transfer matrix theory.When two excited states interact to produce mixed state polaritons,the system is in the strong coupling region,and the energy is coherently exchanged between the two eigenstates.This phenomenon is characterized by Rabi splitting in the spectrum and anti-crossing in the dispersion diagram.Due to the influence of the dielectric constant on the position and intensity of plasmon resonance,a wide range of Rabi splitting energy can be adjusted,which provides a new idea for the study of the interaction of two different Polarons in nanomaterials.Graphs: 52,Forms: 2,References: 218... |
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